As an example of the above ink supply device, there is known an ink-jet image recording apparatus that ejects ink based on an input signal to record an image onto a recording medium such as a recording sheet. The ink-jet image recording apparatus ejects ink supplied to a recording head from a nozzle to thereby record an image on the recording medium.
The recording head is mounted on a carriage and is made to reciprocate in a certain direction with respect to the recording medium. The carriage receives a driving force from a drive source such as a motor to reciprocate in a certain direction while being guided by a guide shaft or a guide tail. During the reciprocating motion of the carriage, ink droplets are selectively ejected from the recording head onto the recording medium. As a result, an image is recorded by the ink droplets landed onto the recording medium.
The ink to be used in the image recording is supplied from an ink tank provided in an ink cartridge so as to store the ink to the recording head mounted on the carriage through a channel member provided in the carriage and is ejected from the recording head. The channel member is a member constituting an ink channel. The channel member is resin-molded.
There is a method using a tube as a method of supplying the ink from the ink tank to the recording head. The tube serves as a channel for flowing the ink from the ink tank to the recording head (more specifically, a channel member) and is flexible enough to follow the reciprocating motion of the carriage. The tube has a length enough to connect the carriage and ink tank even when the carriage is moved to a position farthest from the ink tank. Thus, when the carriage is moved close to the ink tank, the tube is bent.
If an ink-jet image recoding apparatus has a function of recording a color image onto a recording medium, the ink tank and tube are each provided in plural. More specifically, the ink tank and tube are each provided for each of inks of colors (cyan (C), magenta (M), yellow (Y), and black (Bk)).
The plurality of tubes is arranged side-by-side. In a case where the tubes are arranged in a lateral direction (e.g., horizontal direction), a load to be applied when the tubes are bent varies among the tubes. This may cause the carriage connected to the tube to rattle. Further, the tubes are rubbed with each other during movement of the carriage, which may cause noise.
On the other hand, in a case where the tubes are arranged in a vertical direction (e.g., direction of gravitational force), if the ink leaks from a connection between the tube and channel member, the ink that has leaked from the connection of an upper tube may be adhered to the connection of a lower tube. In this state, when the connection of the lower tube and a sub-tank is released for maintenance and the connection thereof is made once again, the ink of the upper tube may go into the lower tube.
The arrangement of the plurality of tubes in the vertical direction is unfavorable for the following reason. In an ink-jet image recording apparatus, the channel member is provided with a damper unit for absorbing dynamic pressure caused by the reciprocating motion of the carriage. The damper unit is designed to be able to increase/decrease a volume of the channel member so as to absorb the dynamic pressure. For example, the damper unit is a film constituting one surface of the channel member. In this configuration, in the case where the plurality of tubes are arranged in the horizontal direction, the above-mentioned film can be shared between the inks of respective colors since a plurality of nozzles formed in the recording head are also arranged in the horizontal direction. That is, the film needs to be provided for only one surface of the ink channels of respective colors formed in the channel member. However, in the case where the plurality of tubes are arranged in the vertical direction, arrangement direction of the channels of the inks of respective colors inside the channel member needs to be changed from the vertical direction to horizontal direction. This complicates a configuration of the ink channels of respective colors inside the channel member, with the result that the film needs to be provided for two or more surfaces, for example, for each color.
To solve the above-described problem, a plurality of tubes is arranged in the vertical direction at a bent portion thereof and changed in arrangement direction at the carriage from the vertical direction to horizontal direction to be connected to connection ports provided in the carriage.